The structure, function, properties, mechanism of action and comparative biochemistry of acid phosphatases will be investigated. Particular attention will be devoted to human prostatic acid phosphatase because of its importance in the diagnosis of prostatic cancer. Studies on invidivual isoenzymes of human liver acid phosphatase, bovine liver acid phosphatase and wheat germ acid phosphatase will be conducted. These studies will include examination of leaving group effects, pH dependence with varied substrates, subunit determinations (on human liver acid phosphatase), phosphoryl-enzyme trapping experiments, irreversible inhibition experiments and the isolation and determination of the composition of active site peptides. Experiments with a novel anionic alkylating agent will be undertaken. The apparent substrate activation of human liver acid phosphatase will be studied with a view towards determining the possible involvement of anti-cooperative half-of-the-sites reactivity.